Instrument assembly with illuminated meter mounting panel

Abstract

A meter mounting panel having an opening through which a dial board of a meter is exposed is made of a transparent material and has a light reflecting surface formed thereon. An edge of the panel is located in the vicinity of a light source so that the light from the light source enters the panel through the edge and is reflected on the reflecting surface to be directed in a direction parallel to the surface of the panel thereby to illuminate the same from within.

What is claimed is: 
     
       1. An instrument assembly, comprising: a casing having a generally open front side;   at least one meter movement disposed in said casing;   a spindle extending from said movement toward the front side of said casing and being rotatable about the axis thereof;   a dial board disposed in said casing in front of said meter movement and having a front face facing the front side of said casing, said front face having indicia thereon and an opening therein through which said spindle passes;   a pointer having a hub portion fixed to said spindle so as to move over the front face of said dial board in response to rotation of said spindle;   a meter mounting panel having a rear edge and a front portion, said front portion positioned in said casing in front of said dial board and having an opening through which the front face of said dial board is exposed, said panel being constructed of a transparent material;   an opaque layer covering at least a portion of the face of said panel which faces away from the front side of said casing;   at least one light source located in said casing at a position to the rear of said dial board for producing light;   a light guiding member which is constructed of a transparent material and is located with respect to said light source and said rear edge of said panel so as to transmit the light from said light source to the edge of said panel; and   means formed on said panel for reflecting the light which has entered the edge of said panel in a direction parallel to the front face of said panel, whereby the reflected light travels in said panel to illuminate the entire of said panel from within.   
     
     
       2. An instrument assembly as claimed in claim 1, in which said light reflecting means comprises a slanted flat surface formed at the edge of said meter mounting panel to provide for internal reflection of light entering the edge of said meter mounting panel from said light guiding member. 
     
     
       3. An instrument assembly as claimed in claim 1, further comprising a colored transparent plate which covers the front face of said meter mounting panel. 
     
     
       4. An instrument assembly as claimed in claim 3, in which said colored transparent plate is formed with a collared opening, the collar being snugly fixed in the opening of said meter mounting panel in a manner to rim the same upon attachment of said plate to said panel. 
     
     
       5. An instrument assembly as claimed in claim 4, in which the peripheral portion of the opening of said meter mounting panel is covered with an opaque layer. 
     
     
       6. An instrument assembly as claimed in claim 1, in which said dial board comprises a transparent plate having an opaque surface layer, said surface layer being partially cut for providing engraved indicia on said dial board. 
     
     
       7. An instrument as claimed in claim 6, in which said transparent plate of the dial board comprises a transparent extension projecting toward said light source for receiving therein the light from said light source, and light reflecting means for reflecting the light entering said extension in a direction parallel to the surface of said dial board thereby to illuminate the engraved indicia on said dial board. 
     
     
       8. An instrument assembly as claimed in claim 7, further comprising pointer illuminating means for illuminating the entire of the pointer which is made of a transparent material, said pointer illuminating means comprising a frusto-conical surface bounding said opening of said dial board, said surface having an apex pointing toward said hub portion of said pointer and a curved surface formed on said hub portion for reflecting the light coming thereinto from said frustoconical surface toward the top of said pointer. 
     
     
       9. An instrument assembly as claimed in claim 8, further comprising a cap on the hub portion of said pointer. 
     
     
       10. An instrument assembly as claimed in claim 7, further comprising dimmer means for independently changing the degree of illumination between the meter mounting panel and the engraved indicia on the dial board, said dimmer means comprising said light source as a first light source and a second light source, a partition member arranged between said first and second light sources to define a first space containing said first light source for illuminating the end of said meter mounting panel, and a second space containing said second light source for independently illuminating an end of said extension of said transparent plate of the dial board, and control means for independently controlling the intensity of brightness of said first and second light sources.